Part I: Prakken's Book on the Formalization of Legal Argumentation 2 Logic and Law

In the field of the formal modeling of legal reasoning, the logic of law, for short, a great deal of research has been performed over the last decade. It is ever wider recognized that logic has more to offer than just the correct use of the classical logical connectives, such as 'if ..., then ...' and '... or ...'. Especially, reasoning with exceptions, conflicts and applicability, all common in law, turn out to be formally analyzable using modern logical techniques. In the late 80s and early 90s, the research on the logic of law got a strong impulse by developments in AI and law, as exemplified by Prakken's (1993) dissertation 'Logical Tools for Modelling Legal Argument'. At the end of 1997, a revised version of Prakken's dissertation was published in Kluwer's Law and Philosophy Library. In the book, the logical aspects of legal reasoning are investigated. Special attention is paid to the defeasibility of legal reasoning. The non-monotonic logics, as they have been developed in artificial intelligence, are an important source of inspiration. The new version of the book contains an adapted formalism (that has been developed by Prakken in cooperation with Giovanni Sartor in the last couple of years) and an updated and extended discussion of related research. The following review of Prakken's book is divided into two parts. Part I (sections 2 to 4) contains the book review proper, and is addressed at the reader with a general interest in artificial intelligence and law. Part II (sections 5 to 9) is mainly aimed at the readers more specifically interested in the logic of law, and consists of comments on Prakken's theory of defeasible argumentation. The comments are meant as a contribution to the ongoing discussion on the nature of defeasible argumentation in the law, and its formalization.